Sampling device

Abstract

The utility model relates to the technical field of sewage sampling, in particular to a sampling device. Universal wheels are fixed to the four end corners of the bottom of the base, an angle adjusting structure is arranged at the position, close to the middle point, of the top of the base, a height adjusting structure is arranged at the top of the angle adjusting structure, and a lifting structure is arranged on one side of the bottom of the height adjusting structure. According to the sampling device provided by the utility model, through the design of the angle adjusting structure, the sampling range of the device is wide, and the actual condition in sewage is accurately reflected; through the design of a height adjusting structure and a lifting structure, it is ensured that the device can accurately obtain samples in water bodies with different depths, and possible missing of key data due to the fixed sampling depth is avoided; and through the design of the leaking stoppage structure, the sampling operation is convenient and efficient, the sampling operation efficiency is greatly improved, and the operation time and the labor cost are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage sampling, in particular to a sampling device. Background Art

[0002] With the improvement of living standards, people pursue a higher quality of life, but this also leads to an increase in sewage and wastewater. These sewage mainly comes from feces and washing sewage in the process of human life, which contains a large amount of organic matter, pathogens, viruses and parasite eggs. In addition, the inorganic salt components in sewage also pollute the environment. However, the traditional sewage sampling device has a complex structure and lacks a cleaning function, which easily causes device contamination and affects the accuracy and reliability of sampling. Therefore, it is particularly important to develop a sewage sampling device with a simple structure, easy to clean and accurate sampling.

[0003] For example, a Chinese utility model patent (CN219573576U) discloses a water treatment environmental monitoring sampling device, which solves the following problems: In actual use, traditional water treatment environmental monitoring sampling devices are mostly used by staff to hold sampling bottles, but manual sampling can only sample the top layer of water near the edge of the treatment pool, and cannot sample the central area of ​​the sewage treatment pool and deep water, resulting in a lack of comparability of samples and limiting the sampling range, which will obviously affect the reliability of the monitoring results.

[0004] The device comprises a base, a support plate is mounted on the top of the base, a rotating rod is rotatably mounted on the support plate, a winding roller is mounted on one end of the rotating rod, a steel element is wound on the winding roller, a sampling bottle is fixedly mounted on the bottom end of the steel cable, a counterweight assembly is mounted on the support plate, the counterweight assembly comprises a positioning plate and a square tube, the positioning plate is fixed on the support plate through a bracket, the square tube is fixed on the positioning plate, and a plurality of counterweight rings are arranged in the square tube. The beneficial effect of the utility model is that the sampling bottle can be moved to any position of the sewage treatment pool by pushing the base to move, the winding roller can be driven to rotate by rotating the rotating rod, and the sampling bottle can be put into the sewage treatment pool conveniently, the weight of the sampling bottle can be increased by the counterweight ring, and the sampling bottle can be ensured to dive to the bottom layer of the sewage treatment pool, which effectively increases the sampling range and ensures that the monitoring result of the sample is more reliable.

[0005] When using the above technology, it was found that the following technical problems exist in the prior art: the device lacks a suitable angle adjustment structure, which makes it impossible for the sampling device to flexibly adjust the sampling angle, thereby limiting its sampling ability under different water flow directions and flow rates. This may lead to the sampling results being incomplete and unable to accurately reflect the actual situation in the sewage. For this reason, we designed a sampling device to provide another technical solution to the above technical problems. Utility Model Content

[0006] Based on this, it is necessary to provide a sampling device to solve the problems raised in the above background technology.

[0007] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0008] A sampling device comprises a base, wherein four end corners of the bottom of the base are fixed with universal wheels, an angle adjustment structure is arranged near the midpoint of the top of the base, a height adjustment structure is arranged on the top of the angle adjustment structure, a lifting structure is arranged on one side of the bottom of the height adjustment structure, a lifting bucket is arranged on the inner side of the lifting structure, and a leak plugging structure is arranged on one side of the lifting bucket.

[0009] As a preferred embodiment of the sampling device provided by the utility model, the angle adjustment structure includes a support block, a first motor, a worm, a worm wheel, a rotating rod and a mounting block, two support blocks are fixed at a position near the midpoint of the top of the base, and the two support blocks are rotatably connected to the sides close to each other with a worm, a first motor is fixed to one side of one of the support blocks, and the output end of the first motor is fixed to the worm, a rotating rod is rotatably connected to the top of the base near the midpoint, a worm wheel is fixed to the outside of the rotating rod, one side of the worm wheel is meshingly connected to the worm, and a mounting block is fixed to the top of the rotating rod.

[0010] As a preferred embodiment of the sampling device provided by the utility model, the height adjustment structure includes a first fixed block, a second motor, a first bevel gear, a second bevel gear, a screw, a screw sleeve, a guide column and a top plate, a first fixed block is fixed to one side of the top of the mounting block, a second motor is fixed to one side of the first fixed block, a first bevel gear is fixed to the output end of the second motor, a screw is rotatably connected to one side of the top of the base, a second bevel gear is fixed to the bottom of the outer side of the screw, the second bevel gear and the first bevel gear are meshed and connected, a screw sleeve is threadedly connected to the outer side of the screw, a top plate is fixed to the top of the screw sleeve, a guide column is fixed to one side of the top of the mounting block, and the guide column and the top plate are slidably connected.

[0011] As a preferred embodiment of the sampling device provided by the utility model, the lifting structure includes a concave plate, a third motor, a rotating wheel, a fixing nail, a first connecting sleeve, a lifting rope and a second connecting sleeve. A concave plate is fixed to one side of the bottom of the top plate, and a third motor is fixed to one side of the concave plate. The inner side of the concave plate is rotatably connected to the rotating wheel, and the output end of the third motor is fixed to the rotating wheel. A fixing nail is fixed to one side of the rotating wheel, and the outer side of the fixing nail is slidably connected to the first connecting sleeve, a lifting rope is fixed to the bottom of the first connecting sleeve, and a second connecting sleeve is fixed to the bottom of the lifting rope.

[0012] As a preferred embodiment of the sampling device provided by the utility model, the lifting structure also includes a connecting rod, a second fixed block, a fixed plate and a connecting block, the inner side of the second connecting sleeve is rotatably connected to the connecting rod, the second fixed blocks are fixed on both sides of the connecting rod, the bottom of the two second fixed blocks are fixed with fixed plates, connecting blocks are fixed on both sides of the bottom of the fixed plate, and the two connecting blocks are fixed to the bucket on one side close to each other.

[0013] As a preferred implementation of the sampling device provided by the utility model, the leak-blocking structure includes a rotating mechanism and a positioning mechanism.

[0014] As a preferred embodiment of the sampling device provided by the utility model, the rotating mechanism includes a rotating rod, a mounting plate and a cam, the rotating rod is rotatably connected to one side of the bucket, the mounting plate is fixed to one side of the bucket, the cam is fixed to the bottom of the rotating rod, and the cam and the bottom of the bucket are slidably connected.

[0015] As a preferred embodiment of the sampling device provided by the utility model, the positioning mechanism includes a mounting disk, a plug stick, a pull block and a spring, the mounting disk is fixed on the outer side of the rotating stick, the plug stick is slidably connected to the inner side of the mounting disk deviating from the center of the circle, the pull block is fixed to the bottom of the plug stick, the outer side of the plug stick is sleeved with a spring, the bottom of the spring is fixed to the pull block, and the top of the spring is fixed to the mounting disk.

[0016] It can be seen without a doubt that the above-mentioned technical solution of the present application can definitely solve the technical problem to be solved by the present application.

[0017] At the same time, through the above technical solutions, the utility model has at least the following beneficial effects:

[0018] The utility model provides a sampling device, which has a wide sampling range through the design of an angle adjustment structure. By adjusting the angle, the sampling device can adapt to different water flow directions and flow rates, so as to perform sampling at different positions and depths, which enables the device to collect sewage samples more comprehensively and accurately reflect the actual situation in the sewage.

[0019] The device is designed with a height adjustment structure and a lifting structure, so that the height of the sampling device can be adjusted as needed, so that sampling can be easily performed in sewage layers of different depths. This flexibility ensures that the device can accurately obtain samples in water bodies of different depths, avoiding the possible omission of key data due to fixed sampling depths;

[0020] The device's leak-plugging structure design makes sampling operations convenient and efficient. Operators can easily and quickly locate and perform sampling work without the need for complicated adjustments or installation steps. This greatly improves the efficiency of sampling operations and reduces operating time and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the overall structure of a sampling device of the utility model;

[0023] Figure 2 It is a side view of a sampling device of the utility model;

[0024] Figure 3 This is a schematic diagram of the connection between a worm and a worm wheel of a sampling device of the utility model;

[0025] Figure 4 This is a schematic diagram of the connection between a screw rod and a screw sleeve of a sampling device of the utility model;

[0026] Figure 5 This is a schematic diagram of the connection between a concave plate and a third motor of a sampling device of the utility model;

[0027] Figure 6 This is a schematic diagram of the connection between the top plate and the concave plate of a sampling device of the utility model;

[0028] Figure 7 This is a schematic diagram of the connection between a fixing plate and a connecting block of a sampling device of the utility model;

[0029] Figure 8 This is a schematic diagram of the connection between the rotating wheel and the fixing nail of a sampling device of the utility model;

[0030] Fig. 9 This is a schematic diagram of the connection between the second fixing block and the fixing plate of a sampling device of the utility model;

[0031] Fig.10 The utility model is a schematic diagram of the connection between a rotating rod and a cam of a sampling device.

[0032] In the figure: 1, base; 2, universal wheel; 3, support block; 4, first motor; 5, worm; 6, worm wheel; 7, rotating rod; 8, mounting block; 9, first fixed block; 10, second motor; 11, first bevel gear; 12, second bevel gear; 13, screw; 14, screw sleeve; 15, guide column; 16, top plate; 17, concave plate; 18, third motor; 19, rotating wheel; 20, fixing nail; 21, first connecting sleeve; 22, lifting rope; 23, second connecting sleeve; 24, connecting rod; 25, second fixed block; 26, fixing plate; 27, connecting block; 28, lifting bucket; 29, rotating stick; 30, mounting plate; 31, cam; 32, mounting plate; 33, plug stick; 34, pull block; 35, spring. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0034] As described in the background technology, the device lacks a suitable angle adjustment structure, which makes it impossible for the sampling device to flexibly adjust the sampling angle, thereby limiting its sampling ability under different water flow directions and flow rates. This may cause the sampling results to be incomplete and unable to accurately reflect the actual situation in the sewage.

[0035] In order to solve this technical problem, the utility model provides a sampling device.

[0036] Specifically, please refer to Figure 1-Figure 10 A sampling device specifically includes: a base 1, four end corners of the bottom of the base 1 are fixed with universal wheels 2, an angle adjustment structure is arranged near the midpoint of the top of the base 1, a height adjustment structure is arranged on the top of the angle adjustment structure, a lifting structure is arranged on one side of the bottom of the height adjustment structure, a lifting bucket 28 is arranged on the inner side of the lifting structure, and a leak-proof structure is arranged on one side of the lifting bucket 28.

[0037] The utility model provides a sampling device, which has a wide sampling range through the design of an angle adjustment structure. By adjusting the angle, the sampling device can adapt to different water flow directions and flow rates, so as to perform sampling at different positions and depths, which enables the device to collect sewage samples more comprehensively and accurately reflect the actual situation in the sewage.

[0038] The device is designed with a height adjustment structure and a lifting structure, so that the height of the sampling device can be adjusted as needed, so that sampling can be easily performed in sewage layers of different depths. This flexibility ensures that the device can accurately obtain samples in water bodies of different depths, avoiding the possible omission of key data due to fixed sampling depths;

[0039] The device's leak-plugging structure design makes sampling operations convenient and efficient. Operators can easily and quickly locate and perform sampling work without the need for complicated adjustments or installation steps. This greatly improves the efficiency of sampling operations and reduces operating time and labor costs.

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0042] Reference Figure 1-Figure 10 A sampling device comprises a base 1, universal wheels 2 are fixed to the four end corners of the bottom of the base 1, an angle adjustment structure is arranged near the midpoint of the top of the base 1, a height adjustment structure is arranged on the top of the angle adjustment structure, a lifting structure is arranged on one side of the bottom of the height adjustment structure, a lifting bucket 28 is arranged on the inner side of the lifting structure, and a leak plugging structure is arranged on one side of the lifting bucket 28.

[0043] The angle adjustment structure includes a support block 3, a first motor 4, a worm 5, a worm wheel 6, a rotating rod 7 and a mounting block 8. Two support blocks 3 are fixed to the top of the base 1 near the midpoint, and the two support blocks 3 are rotatably connected to the sides close to each other with the worm 5. A first motor 4 is fixed to one side of one of the support blocks 3, and the output end of the first motor 4 is fixed to the worm 5. A rotating rod 7 is rotatably connected to the top of the base 1 near the midpoint, a worm wheel 6 is fixed to the outside of the rotating rod 7, and one side of the worm wheel 6 is meshed with the worm 5. A mounting block 8 is fixed to the top of the rotating rod 7, so that the angle adjustment structure can adjust the angle of the mounting block 8.

[0044] The height adjustment structure includes a first fixed block 9, a second motor 10, a first bevel gear 11, a second bevel gear 12, a screw 13, a screw sleeve 14, a guide column 15 and a top plate 16. The first fixed block 9 is fixed to one side of the top of the mounting block 8, the second motor 10 is fixed to one side of the first fixed block 9, the first bevel gear 11 is fixed to the output end of the second motor 10, the screw 13 is rotatably connected to one side of the top of the base 1, the second bevel gear 12 is fixed to the bottom of the outer side of the screw 13, the second bevel gear 12 and the first bevel gear 11 are meshed and connected, the screw sleeve 14 is threadedly connected to the outer side of the screw 13, the top plate 16 is fixed to the top of the screw sleeve 14, the guide column 15 is fixed to one side of the top of the mounting block 8, the guide column 15 and the top plate 16 are slidably connected, so that the height adjustment structure can adjust the height of the top plate 16.

[0045] The lifting structure includes a concave plate 17, a third motor 18, a rotating wheel 19, a fixing nail 20, a first connecting sleeve 21, a lifting rope 22, a second connecting sleeve 23, a connecting rod 24, a second fixing block 25, a fixing plate 26 and a connecting block 27. The concave plate 17 is fixed to one side of the bottom of the top plate 16, the third motor 18 is fixed to one side of the concave plate 17, the rotating wheel 19 is rotatably connected to the inner side of the concave plate 17, the output end of the third motor 18 is fixed to the rotating wheel 19, the fixing nail 20 is fixed to one side of the rotating wheel 19, and the outer side of the fixing nail 20 A first connecting sleeve 21 is slidably connected, a lifting rope 22 is fixed to the bottom of the first connecting sleeve 21, a second connecting sleeve 23 is fixed to the bottom of the lifting rope 22, a connecting rod 24 is rotatably connected to the inner side of the second connecting sleeve 23, second fixing blocks 25 are fixed on both sides of the connecting rod 24, fixing plates 26 are fixed to the bottoms of the two second fixing blocks 25, connecting blocks 27 are fixed on both sides of the bottom of the fixing plates 26, and the two connecting blocks 27 are fixed to the lifting bucket 28 on the sides close to each other, so that the lifting structure can drive the lifting bucket 28 to rise and fall.

[0046] The leak-proof structure includes a rotating mechanism and a positioning mechanism. The rotating mechanism includes a rotating rod 29, a mounting plate 30 and a cam 31. The rotating rod 29 is rotatably connected to one side of the bucket 28, and the mounting plate 30 is fixed to one side of the bucket 28. The cam 31 is fixed to the bottom of the rotating rod 29. The cam 31 is slidably connected to the bottom of the bucket 28, so that the rotating mechanism can drive the cam 31 to rotate.

[0047] The positioning mechanism includes a mounting plate 32, a plugging rod 33, a pulling block 34 and a spring 35. The mounting plate 32 is fixed to the outer side of the rotating rod 29, the plugging rod 33 is slidably connected to the inner side of the mounting plate 32 deviating from the center of the circle, the pulling block 34 is fixed to the bottom of the plugging rod 33, and the spring 35 is sleeved and connected to the outer side of the plugging rod 33. The bottom of the spring 35 is fixed to the pulling block 34, and the top of the spring 35 is fixed to the mounting plate 32, so that the positioning mechanism can limit the rotation of the rotating rod 29.

[0048] The utility model provides a sampling device, which has a wide sampling range through the design of an angle adjustment structure. By adjusting the angle, the sampling device can adapt to different water flow directions and flow rates, so as to perform sampling at different positions and depths, which enables the device to collect sewage samples more comprehensively and accurately reflect the actual situation in the sewage.

[0049] The device is designed with a height adjustment structure and a lifting structure, so that the height of the sampling device can be adjusted as needed, so that sampling can be easily performed in sewage layers of different depths. This flexibility ensures that the device can accurately obtain samples in water bodies of different depths, avoiding the possible omission of key data due to fixed sampling depths;

[0050] The device's leak-plugging structure design makes sampling operations convenient and efficient. Operators can easily and quickly locate and perform sampling work without the need for complicated adjustments or installation steps. This greatly improves the efficiency of sampling operations and reduces operating time and labor costs.

[0051] The use process of a sampling device provided by the utility model is as follows: the user pushes the device to the location where sampling is required, and then energizes the second motor 10 to rotate, and the output end of the second motor 10 drives the first bevel gear 11 to rotate. Since one side of the first bevel gear 11 is meshedly connected with the second bevel gear 12, the rotation of the first bevel gear 11 drives the second bevel gear 12 to rotate, and the rotation of the second bevel gear 12 drives the screw 13 to rotate. Since the outer side of the screw 13 is threadedly connected with the screw sleeve 14, the rotation of the screw 13 drives the screw sleeve 14 to rotate, and then drives the top plate 16 to slide and rise on the outer side of the guide column 15. The user inserts the bucket 28 into the sewage pool, and then energizes the first motor 4 to rotate, and the output end of the first motor 4 drives the worm 5 to rotate. Since one side of the worm 5 is meshedly connected with the worm wheel 6, the rotation of the worm 5 drives the worm wheel 6 to rotate, and then drives the mounting block 8 to rotate, so that the device can It can flexibly adapt to various needs, and can easily cope with both calm water surface and turbulent water flow, thereby improving the applicability and flexibility of the equipment; the user energizes the third motor 18 to rotate, thereby driving the rotating wheel 19 to rotate, and the rotation of the rotating wheel 19 drives the fixing nail 20 to rotate, thereby driving the lifting rope 22 to rotate, and lifts the lifting bucket 28. When it is necessary to collect the sewage inside the lifting bucket 28, the user pulls open the pull block 34, thereby stretching the spring 35, so that the plug 33 is disengaged from the plug connection with the mounting plate 30, and the user rotates the rotating stick 29 and the cam 31, thereby enabling the cam 31 to be disengaged from the sliding connection with the lifting bucket 28, thereby allowing the water source inside the lifting bucket 28 to be poured out from the inside of the lifting bucket 28, thereby improving the flexibility of the device. The utility model can provide a wider, more convenient and more adaptable sampling capability, while improving data quality, bringing many advantages to sewage treatment and monitoring work.

[0052] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and the specification only describe the principles of the utility model. The utility model may be subject to various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A sampling device, comprising a base (1), characterized in that: Universal wheels (2) are fixed to the four end corners of the bottom of the base (1); an angle adjustment structure is provided at a position close to the midpoint of the top of the base (1); a height adjustment structure is provided at the top of the angle adjustment structure; a lifting structure is provided on one side of the bottom of the height adjustment structure; a lifting bucket (28) is provided on the inner side of the lifting bucket (28); and a leak-blocking structure is provided on one side of the lifting bucket (28).

2. A sampling device according to claim 1, characterized in that: The angle adjustment structure comprises a support block (3), a first motor (4), a worm (5), a worm wheel (6), a rotating rod (7) and a mounting block (8); two support blocks (3) are fixed at positions near the midpoint of the top of the base (1); the two support blocks (3) are rotatably connected to one side thereof close to each other with a worm (5); a first motor (4) is fixed at one side of one of the support blocks (3); an output end of the first motor (4) is fixed to the worm (5); a rotating rod (7) is rotatably connected to the top of the base (1) near the midpoint; a worm wheel (6) is fixed to the outer side of the rotating rod (7); one side of the worm wheel (6) is meshingly connected to the worm (5); and a mounting block (8) is fixed at the top of the rotating rod (7).

3. A sampling device according to claim 2, characterized in that: The height adjustment structure comprises a first fixed block (9), a second motor (10), a first bevel gear (11), a second bevel gear (12), a screw (13), a screw sleeve (14), a guide column (15) and a top plate (16); the first fixed block (9) is fixed to one side of the top of the mounting block (8); the second motor (10) is fixed to one side of the first fixed block (9); the output end of the second motor (10) is fixed to the first bevel gear (11); the screw (13) is rotatably connected to one side of the top of the base (1); the second bevel gear (12) is fixed to the bottom of the outer side of the screw (13); the second bevel gear (12) and the first bevel gear (11) are meshingly connected; the screw sleeve (14) is threadedly connected to the outer side of the screw (13); the top plate (16) is fixed to the top of the screw sleeve (14); the guide column (15) is fixed to one side of the top of the mounting block (8); the guide column (15) and the top plate (16) are slidably connected.

4. A sampling device according to claim 3, characterized in that: The lifting structure comprises a concave plate (17), a third motor (18), a rotating wheel (19), a fixing nail (20), a first connecting sleeve (21), a lifting rope (22) and a second connecting sleeve (23); the concave plate (17) is fixed to one side of the bottom of the top plate (16); the third motor (18) is fixed to one side of the concave plate (17); the inner side of the concave plate (17) is rotatably connected to the rotating wheel (19); the output end of the third motor (18) is fixed to the rotating wheel (19); the fixing nail (20) is fixed to one side of the rotating wheel (19); the outer side of the fixing nail (20) is slidably connected to the first connecting sleeve (21); the bottom of the first connecting sleeve (21) is fixed to the lifting rope (22); the bottom of the lifting rope (22) is fixed to the second connecting sleeve (23).

5. A sampling device according to claim 4, characterized in that: The lifting structure further comprises a connecting rod (24), a second fixed block (25), a fixed plate (26) and a connecting block (27); the inner side of the second connecting sleeve (23) is rotatably connected to the connecting rod (24); the second fixed blocks (25) are fixed on both sides of the connecting rod (24); the bottoms of the two second fixed blocks (25) are fixed with fixed plates (26); the two sides of the bottom of the fixed plate (26) are fixed with connecting blocks (27); and the sides of the two connecting blocks (27) close to each other are fixed to the lifting bucket (28).

6. A sampling device according to claim 5, characterized in that: The leak-blocking structure comprises a rotating mechanism and a positioning mechanism.

7. A sampling device according to claim 6, characterized in that: The rotating mechanism comprises a rotating rod (29), a mounting plate (30) and a cam (31); one side of the lifting bucket (28) is rotatably connected to the rotating rod (29); one side of the lifting bucket (28) is fixed with the mounting plate (30); the bottom of the rotating rod (29) is fixed with the cam (31); the cam (31) and the bottom of the lifting bucket (28) are slidably connected.

8. A sampling device according to claim 7, characterized in that: The positioning mechanism comprises a mounting plate (32), a plugging rod (33), a pulling block (34) and a spring (35); the mounting plate (32) is fixed on the outer side of the rotating rod (29); the plugging rod (33) is slidably connected to the inner side of the mounting plate (32) deviating from the center of the circle; the pulling block (34) is fixed to the bottom of the plugging rod (33); the outer side of the plugging rod (33) is sleeve-connected with a spring (35); the bottom of the spring (35) is fixed to the pulling block (34); and the top of the spring (35) is fixed to the mounting plate (32).

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